Within the field of nanotechnology, interest has arisen in obtaining nanostructures through the use of microorganisms. In general, it is recognized within the prior art that methods using microorganisms are more efficient than chemical or physical methods in terms of cost and environmental impact.
In the state of the art, processes have been reported using bacteria to obtain nanostructures of arsenic sulfide (As—S). For example, patent application US 2014/239,249 discloses a method of manufacturing As—S nanofibers using the bacterium Shewanella sp. ANA-3. On the other hand, U.S. Pat. No. 8,012,727 describes a method for making nanotubes of As2S3 that possess photoconductivity, using the bacterium Shewanella sp. HN-41, and to a lesser extent As—S in the form of tubes.
A method of biogenic manufacture of nanoparticles and quantum dots is also disclosed in U.S. Pat. No. 8,465,721. In this case, the nanoparticles obtained are a combination of an element of groups 15 or 16 (such as Sulfur or Arsenic) and one or more metals of groups 11, 12, 13 or 14. To recover the nanoparticles or quantum dots from the culture medium, the document mentions the possibility of acidifying the medium to induce a cellular flocculation and then centrifuging.
Prior art documents, however, do not mention the possibility of using other strains for the biogenic production of As—S nanostructures, nor do they mention the possibility of extracting both nanowires and nanoparticles from, essentially, the same process.